@roseincalifornia coincidentally I had an appointment today with my endocrinologist who did seem to be somewhat perplexed by the fact that my P1 NP marker went up but my NTX, which is similar to the CTX, but on a different scale, more than tripled and should not have gone up that dramatically. Bone resorption appears to be out pacing bone formation. She did feel it was too early for Tymlos to show an effect and when I asked her how we would ever know, she said you really don’t know whether Tymlos is working, at least in my case. I said, I guess I need to take a hard fall and if I don’t break anything, I’m OK. She smiled. She has known me for many years. She did say there were bone study centers but it would take a bit of travel to get to one . I’m in Florida, and I believe the closest that she mentioned was at Duke university. I’m afraid the science is not absolute and in cases like mine where neither hips nor spine are available for accurate analysis, I just have to keep my fingers crossed. I jokingly tell my friends I’m melting.